This invention relates to devices for delivering brachytherapy seeds to an individual.
Brachytherapy is a form of cancer treatment in which radiation sources are placed inside a patient""s body to irradiate a tumor. In brachytherapy, a surgeon usually implants several radioactive seeds in or around a tumor, thus providing a radiation dose to the tumor. Careful placement of the radioactive seeds allows localized and precise irradiation of the tumor. Because the radiation dose diminishes rapidly outside the radioactive seed, the radiation dose to surrounding healthy tissues is minimized. Many forms of cancer respond to brachytherapy, including several forms of prostate cancer. Brachytherapy generally is less invasive than surgery, usually results in fewer side effects than surgery or external beam radiation, allows for a short recovery time, and reduces the impact on the patient""s quality of life.
The invention features brachytherapy applicators for delivering radioactive seeds to a patient. Specifically, the invention provides brachytherapy applicators in which a seed magazine is removably held within a chuck by a magazine retaining structure. The magazine retaining structures described herein are designed such that a seed magazine can be readily inserted into or removed from a brachytherapy applicator.
During brachytherapy procedures, blood cells can migrate from the patient into the applicator. These blood cells and other contaminants can become lodged in the applicator at or near the magazine retaining structure. The magazine retaining structures provided by the invention are designed such that they will not become jammed when blood cells or other particles enter the applicator during a brachytherapy procedure and remain in the applicator during cleaning and autoclaving. Clinicians performing brachytherapy procedures therefore can quickly and easily insert and remove empty magazines from the applicators provided herein, and can be assured that newly inserted seed magazines will be firmly held in place.
The invention features a brachytherapy applicator containing a needle and a chuck. The chuck can contain a slot for receiving a magazine containing radioactive seeds, and the chuck can be positioned such that seeds are delivered from the magazine to the needle. The chuck can contain a magazine retaining structure selected from the group consisting of a solid component and a component that contains at least two openings.
The magazine retaining structure can include a leaf spring having at least one protrusion (e.g., a ball like feature). The chuck can define a vent positioned behind the leaf spring. The magazine retaining structure can include a wire having a bulge. The chuck can define a groove, and the wire can be in the groove. The chuck can define a vent positioned behind the bulge. The magazine retaining structure can include a Bellville spring having a protrusion (e.g., a central dome). The chuck can define a vent positioned behind the Bellville spring.
The magazine retaining structure can be a component that contains at least two openings. The magazine retaining structure can include a hollow shell having a first end, wherein the first end defines an opening, and wherein the shell defines a vent, the opening and the vent being the at least two openings. The magazine retaining structure also can include a ball, wherein the shell retains the ball such that the ball is movably positioned at least partially within the shell, and a spring, wherein the shell retains the spring such that the spring exerts force against the ball such that the ball is pushed toward the first end to a position where the ball partially protrudes through the opening. The shell can define a second end, and the vent can be positioned at the second end. The shell can define a side region, and the vent can be positioned in the side region. The vent can be accessible through the chuck. At least a portion of an outer surface of the shell can contain a thread. The chuck can define first and second side portions, and at least one of the side portions can define an opening capable of receiving the magazine retaining structure. The magazine retaining structure can be removable from the applicator. The magazine retaining structure can be plastic, bronze, or stainless steel.
In another aspect, the invention features a brachytherapy applicator containing a needle and a chuck. The chuck can define a slot for receiving a magazine containing radioactive seeds, wherein the chuck is positioned such that the seeds are delivered from the magazine to the needle. The chuck also can contain a magazine retaining structure, wherein the magazine retaining structure includes a hollow shell defining a first end and a second end, wherein the first end defines an opening; a ball, wherein the ball is movably positioned at least partially within the hollow shell; and a spring, wherein the spring exerts force against the ball in a direction toward the first end such that the ball partially protrudes through the opening, and wherein at least one open space exists when the ball is fully engaged within the opening. The hollow shell can define a vent (e.g., a vent at the second end or a vent in a side region).
The invention also features a ball-plunger device containing a hollow shell, a ball, and a spring. The hollow shell can define a first end and an outer surface, wherein the first end defines an opening, and wherein the outer surface defines at least one thread and at least one vent. The ball can be movably positioned at least partially within the hollow shell. The spring can exert force against the ball in a direction toward the first end such that the ball partially protrudes through the opening. The hollow shell can define a second end, and the vent can be positioned at the second end. The hollow shell can define a side region, and the vent can be positioned in the side region. The hollow shell can define a second end, wherein the second end defines a head, and wherein the head contains a recess adapted to receive the mating end of an installation tool (e.g., a Phillips screwdriver). The head can contain a vent.
In another aspect, the invention features a hollow screw containing a shell structure, a ball and a spring. The shell structure can defines a first end and an outer surface, the first end can define an opening, the outer surface can define a vent, and at least a portion of the outer surface can contain a thread. The ball can be movably positioned at least partially within the shell structure. The spring can be positioned within the shell structure such that the spring exerts force against the ball in a direction toward the opening. The shell structure can define a second end, wherein the second end defines a head. The head can define the vent. The ball can protrude from the shell structure to a distance between about 0.01 inch and 0.1 inch.
In yet another aspect, the invention features a hollow screw containing a plastic shell structure, a ball, and a spring. The plastic shell structure can define a first end and an outer surface, wherein the first end defines an opening, and wherein at least a portion of the outer surface defines a thread. The ball can be movably positioned at least partially within the shell structure. The spring can be positioned within the shell structure such that the spring exerts force against the ball in a direction toward the opening. The shell structure can defines a second end, wherein the second end defines a head, and wherein the head defines a vent. The head can define a recess adapted to receive the mating end of an installation tool (e.g., a Phillips screwdriver).
The invention also features a hollow plastic screw containing a shell structure, a ball, and a spring. The shell structure can define a first end, a head, and an outer surface, wherein the first end defines an opening, and wherein at least a portion of the outer surface defines a thread. The ball can be movably positioned at least partially within the shell structure. The spring can be positioned within the shell structure such that the spring exerts force against the ball in a direction toward the opening. The head can define a recess adapted to receive the mating end of an installation tool (e.g., a Phillips screwdriver).
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although methods and materials similar or equivalent to those described herein can be used to practice the invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.